210 
THE BORDERLAND OP CHEMISTRY AND ELECTRICITY. 
Stahl first evolutionised the name Phlogiston; this Phlogiston, 
given off by combustion, he found to be taken up by living 
plants; and he supposed that the phenomena of fermentation and 
decay were due to a loss of Phlogiston; between the announcement 
of the Phlogistic theories and its complete disestablishment by 
Lavoisier, the science was built up by Black, Priestley and Cavendish. 
Black (1754) shook the foundation of the Phlogiston theory and 
was the first to bring forth Quantitative Chemistry, as he introduced 
the balance or scales, an instrument absolutely necessary for all 
chemical science and research; Black showed that the effervescence 
produced when magnesia alba or carbonate of magnesia was acted on 
by an acid resulted in the loss of weight of the original materials, viz. 
by adding a given weight of acid to a given weight of this magnesia 
alba or carbonate of magnesia a gas is given off. On re-weighing the 
compound formed by the two materials it is easily seen that the re¬ 
sultant weight is less than the original weights of the two materials 
before mixture. 
Priestley, in 1772, examined the chemistry of the burning of candles, 
and the breathing of animals upon air; he then found that living 
plants placed in the gas vitiated by the breathing of animals or the 
combustion of a candle reconverted the deteriorated air to its original 
property, viz., of again supporting the combustion of a candle; by 
this simple experiment the world was first taught the absolute necessity 
of growing plants and trees as a means of purifying air rendered 
noxious by animal life, and the fires and lights of the habitations of 
men. Without this natural purifying process the air would become 
incapable of supporting life, and universal death to life as we know it 
must slowly and surely come; the gases producing this deleterious 
effect are known as carbonic acid and carbonic oxide. It must be re¬ 
membered that the atmosphere of our world is not inexhaustible, and 
if the balance of nature is upset by man, so that with his many in¬ 
ventions necessitating the enormous consumption of the oxygen of the 
air for the purpose of producing the necessary requirements of heat 
and combustion, oxygen will become so scarce that animal life, and 
for the matter of that vegetable life, will cease to exist. It is there¬ 
fore necessary to take care that the balance so beautifully adjusted by 
nature should not be destroyed by man’s rapacious worship of the 
golden calf, for the chief cause of the vitiation of the atmosphere is 
due to the piling-up of wealth. To stop this, chemical and physical 
knowledge may in future ages so evolutionise that the natural force 
of nature will be used for producing heat, light, and power, instead of 
the artificial force now used by man. To cheapen coal gas, water gas 
is now added; carbonic oxide is thus added to atmospheres of our 
rooms, producing headache, giddiness and fainting, even when present 
in minute quantities. I have also detected Fluorine compounds in the 
atmosphere of manufacturing rooms. Is it true that bone manure 
manufacturers use large amounts of natural fluorides ? The gases 
driven off from these compounds by heat and wind reactions, vitiate 
